Simple: the HENSA server is broken.
You wrote:
>> >You can provide no guarantee that the versions that you present to your
>> >users are accurate or timely.
I took the "You" in that sentence to mean you, the caching server
administrator. It is simply not true that the HENSA server
administrator _can not_ provide a reasonable guarantee that his
readers get timely information. This is why I spoke up: so that
www-talk readers don't come away thinking what you said is the only
way it can be.
It's a simple matter of server configuration. As I recall, the CERN
http daemon's default configuration is "correct" as per the protocol,
i.e. it doesn't do any heuristic caching -- it only caches HTTP
requests with an explicit Expires: header in the response. They do
document the configuration options for heuristics like "cache FTP
stuff for 2 days."
I think it's even possible to say "cache GIFs for two weeks, except
for the dilbert comics from ora.com," if you're so inclined.
The point is: please don't generalize certain broken installations and
implementations into a condemnation of the WWW architecture as a
whole. I agree that WWW has a long way to go before it is consumer
technology, but perception has a lot to do with it's deployment. Let's
not give the wrong impression at this critical stage.
Dan